1. Field of the Invention
This invention relates to buckles for removably attaching strap or webbing ends together and more particularly to such a buckle that operates with two distinct locking and release actions.
2. Description of the Related Art
Double locking safety buckles such as described in U.S. Pat. No. 3,728,764 issued Apr. 24, 1973 to Carter have been in use for some time. What is meant by xe2x80x9cdouble lockingxe2x80x9d is that two distinct and separate actions are required by the user to both lock and release the buckle. In certain jurisdictions, such double action on safety buckles used in harnesses employed in hazardous situations are required by legal regulations. Typical applications for such a safety buckle are parachute harnesses, harnesses for persons working at heights or other dangerous environments. This type of buckle could also be used in tying down cargo during transportation or in attaching together two sections of a web or strap used for lifting cargo or personnel.
For a double acting safety buckle to perform its function properly, two separate and distinct actions in locking and releasing the buckle should be provided. Both actions should be such that a likelihood of accidental unlocking is minimized. Along these lines, many of the prior art devices utilize button releases for one of the actions. This type of release has the disadvantage of being readily subject to accidental actuation. While it is necessary to minimize the possibilities of accidental release, the buckle at the same time should be releasable by the user without undue difficulty.
Also, many of the prior art double acting locking buckles are overly complicated in their construction which makes for greater cost, less reliability, and shorter service life.
The device of the present invention is an improvement over the prior art in that it provides a double locking buckle which has two separate and distinct locking actions, neither of which is prone to accidental actuation. Further, the device of the present invention incorporates means for easily tightening the web or strap. In addition, the device of the present invention is of simple constructions utilizing a minimum number of parts and is of economical and reliable construction.
In the device of the invention, there are only three basic parts, a frame, a latch member, and an adjuster member. The latch member is pivotally supported on the frame by means of a support shaft which is attached to the frame. A first strap end portion is fixedly attached to one end of the frame. A second strap end portion to be attached to the first strap end portion is removably attached to one end of the adjuster member by suitable means such as reeving through slots formed on the adjuster member so that the effective length of the strap can be readily adjusted in tightening and loosening the strap. The opposite end of the adjuster member has a T-shaped configuration.
The frame has a pair of opposing ledge portions which extend opposite the base portion of the frame, opposing slots being formed in the ledge portions. The top of the xe2x80x9cTxe2x80x9d of the adjuster member fits into the slots formed in the frame to retain the adjuster member to the frame when tension is placed on the second strap end portion, thereby providing a first locking action. The latch member has a pair of opposing side portions which have slots formed therein. The latch member further has detents formed thereon which engage detents formed on the bottom ends of the ledge portions of the frame and snap thereunder to hold the latch member in position against the end of the adjuster member. The ends of the xe2x80x9cTxe2x80x9d of the adjuster member fit into the latch member slots, thereby reinforcing the retention of the adjuster member to the frame. The adjuster member is thus retained to the frame even without tension on the straps, thereby providing the second locking action.
In a second embodiment of the invention, the adjuster member has longitudinal slots formed near one end thereof into which the portions of the side portion of the frame adjacent to the slots fit to provide the first locking action; the side portions of the frame member also fitting into these slots to provide the second locking action.
It is therefore an object of this invention to provide an improved double locking adjustable buckle which is of more reliable and economical construction.
It is a further object of this invention to provide a double locking adjustable buckle which provides two distinct locking actions neither of which is susceptible to accidental unlocking.
Other objects of the invention will become apparent in view of the following description taken in connection with the accompanying drawings.